From 91dbfb2a8f466cf30f7b02cbc6f3e89376d31c59 Mon Sep 17 00:00:00 2001 From: Tiark Rompf Date: Tue, 29 Nov 2011 18:56:51 +0000 Subject: improve cps handling of if-then-else. no review. --- .../tools/selectivecps/SelectiveANFTransform.scala | 62 ++++++++++++---------- 1 file changed, 33 insertions(+), 29 deletions(-) (limited to 'src') diff --git a/src/continuations/plugin/scala/tools/selectivecps/SelectiveANFTransform.scala b/src/continuations/plugin/scala/tools/selectivecps/SelectiveANFTransform.scala index 9f1d3dfcd6..b383227243 100644 --- a/src/continuations/plugin/scala/tools/selectivecps/SelectiveANFTransform.scala +++ b/src/continuations/plugin/scala/tools/selectivecps/SelectiveANFTransform.scala @@ -173,40 +173,44 @@ abstract class SelectiveANFTransform extends PluginComponent with Transform with (Nil, tree1, cpsA) - case If(cond, thenp, elsep) => - - val (condStats, condVal, spc) = transInlineValue(cond, cpsA) - - val (cpsA2, cpsR2) = (spc, linearize(spc, getAnswerTypeAnn(tree.tpe))) -// val (cpsA2, cpsR2) = (None, getAnswerTypeAnn(tree.tpe)) - val thenVal = transExpr(thenp, cpsA2, cpsR2) - val elseVal = transExpr(elsep, cpsA2, cpsR2) - - // check that then and else parts agree (not necessary any more, but left as sanity check) - if (cpsR.isDefined) { - if (elsep == EmptyTree) - unit.error(tree.pos, "always need else part in cps code") - } - if (hasAnswerTypeAnn(thenVal.tpe) != hasAnswerTypeAnn(elseVal.tpe)) { - unit.error(tree.pos, "then and else parts must both be cps code or neither of them") - } + case If(cond, thenp, elsep) => + /* possible situations: + cps before (cpsA) + cps in condition (spc) <-- synth flag set if *only* here! + cps in (one or both) branches */ + val (condStats, condVal, spc) = transInlineValue(cond, cpsA) + val (cpsA2, cpsR2) = if (hasSynthMarker(tree.tpe)) + (spc, linearize(spc, getAnswerTypeAnn(tree.tpe))) else + (None, getAnswerTypeAnn(tree.tpe)) // if no cps in condition, branches must conform to tree.tpe directly + val thenVal = transExpr(thenp, cpsA2, cpsR2) + val elseVal = transExpr(elsep, cpsA2, cpsR2) + + // check that then and else parts agree (not necessary any more, but left as sanity check) + if (cpsR.isDefined) { + if (elsep == EmptyTree) + unit.error(tree.pos, "always need else part in cps code") + } + if (hasAnswerTypeAnn(thenVal.tpe) != hasAnswerTypeAnn(elseVal.tpe)) { + unit.error(tree.pos, "then and else parts must both be cps code or neither of them") + } - (condStats, updateSynthFlag(treeCopy.If(tree, condVal, thenVal, elseVal)), spc) + (condStats, updateSynthFlag(treeCopy.If(tree, condVal, thenVal, elseVal)), spc) - case Match(selector, cases) => + case Match(selector, cases) => - val (selStats, selVal, spc) = transInlineValue(selector, cpsA) - val (cpsA2, cpsR2) = (spc, linearize(spc, getAnswerTypeAnn(tree.tpe))) -// val (cpsA2, cpsR2) = (None, getAnswerTypeAnn(tree.tpe)) + val (selStats, selVal, spc) = transInlineValue(selector, cpsA) + val (cpsA2, cpsR2) = if (hasSynthMarker(tree.tpe)) + (spc, linearize(spc, getAnswerTypeAnn(tree.tpe))) else + (None, getAnswerTypeAnn(tree.tpe)) - val caseVals = for { - cd @ CaseDef(pat, guard, body) <- cases - bodyVal = transExpr(body, cpsA2, cpsR2) - } yield { - treeCopy.CaseDef(cd, transform(pat), transform(guard), bodyVal) - } + val caseVals = for { + cd @ CaseDef(pat, guard, body) <- cases + bodyVal = transExpr(body, cpsA2, cpsR2) + } yield { + treeCopy.CaseDef(cd, transform(pat), transform(guard), bodyVal) + } - (selStats, updateSynthFlag(treeCopy.Match(tree, selVal, caseVals)), spc) + (selStats, updateSynthFlag(treeCopy.Match(tree, selVal, caseVals)), spc) case ldef @ LabelDef(name, params, rhs) => -- cgit v1.2.3